1. Field of the Invention
This invention relates to vehicle wheel assemblies and to components of these wheel assemblies.
2. Description of the Prior Art
Vehicle wheel assemblies conventionally include a wheel hub that rotatably mounts an associated wheel on a vehicle axle. The hub is conventionally manufactured as a steel forging or casting and has an annular configuration. A central opening of the hub includes bearing seats for receiving antifriction bearings that rotatably support the hub on the axle. The hub also includes provisions for supporting a vehicle brake component, such as a drum or a disc, used in the braking action of the vehicle. At its outer extremity, the hub includes provisions for supporting an associated vehicle wheel.
Conventional automotive wheels include an annular rim that supports an associated tire. A disc of the wheel is secured to the rim within its annular configuration. The central portion of the wheel disc includes holes for receiving bolts which detachably secure the wheel to an associated hub. The wheel rim and disc are conventionally made by forging of steel stock that is of a relatively heavy gauge, i.e. on the order of one-eighth inch thickness. The outer periphery of the disc is fixedly secured to the rim by welding so that the rim and disc are inseparable. The point of separation between the components of the automotive wheel assembly thus occurs at the wheel disc and hub during replacement or repair of the associated vehicle tire. This necessarily means that each automotive vehicle having four wheel assemblies being utilized and one spare tire requires five wheels having a rim and disc. The forging process of the relatively heavy steel stock from which the wheel components are made must be carried out with sufficient accuracy so that no unbalanced forces are present during the rotation of the wheel. The heavy stock from which the wheel is forged makes this balancing somewhat more difficult than would be the case if lighter stock were utilized. However, to provide the required structural strength, such heavy stock is necessary with conventional automotive wheels.
U.S. Pat. application Ser. No. 527,555, filed Nov. 27, 1974, and now U.S. Pat. No. 3,968,996, discloses an automotive wheel whose attached rim and disc are manufactured from an outer steel skin that defines a single cavity for receiving load bearing foam that cooperates with the skin in carrying the wheel load. The rim and disc portions of this wheel are integrally formed with each other so that separation during tire repair or replacement occurs between the wheel disc portion and the hub.
Vehicle wheel assemblies of the more heavy-duty type for use on trucks or trailers have a somewhat different construction than automotive wheel assemblies. These heavy-duty wheel assembly constructions conventionally include a wheel hub that is cast or forged from steel. The disc portion of the wheel may be integral with the hub and support the brake drum or brake disc of the wheel assembly. The outer periphery of the integral hub and wheel disc detachably supports one or more wheel rims for carrying one or more tires. The heavy-duty wheel assembly construction may also take another form wherein the rim and disc portions of the wheel are welded to each other and detachably secured to the wheel hub. In this construction, the brake drum or brake disc is fixedly secured to the hub. Both of these heavy-duty wheel assembly constructions require a relatively large amount of machining to provide the balanced wheel assembly necessary.
U.S. Pat. No. 3,874,055 discloses a method of making a vehicle wheel that is particularly designed for use as a heavyduty truck or trailer type wheel. The disc portion of this wheel is manufactured from a continuous metallic strip that is stamped to define retaining flanges. The stamped strip is then coiled into a single closed loop that is stamped radially to define spoke-like components. The central portion defined by these spoke-like components is secured to a cast or forged hub. The periphery of this stamped structure is detachably secured to a pair of rims to complete the assembly. The hub and rims of this wheel assembly are both forged or cast and may require machining to provide the necessary balance.